ATAVRQTOUCHX Atmel, ATAVRQTOUCHX Datasheet - Page 43

• Manufacturer Part Number: ATAVRQTOUCHX
• Description: BOARD EVAL CAPACITIVE TOUCH
• Manufacturer: Atmel
• Series: QTouch™r

Specifications of ATAVRQTOUCHX

• Sensor Type: Touch, Capacitive
• Sensing Range: 1 Slider, 1 Wheel, 2 Buttons
• Interface: USB
• Voltage - Supply: 5V, USB
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: AT90USB1287, ATxmega128A1
• Silicon Manufacturer: Atmel
• Silicon Family Name: ATxmega
• Kit Contents: Board
• Svhc: No SVHC (15-Dec-2010)
• Core Architecture: AVR
• Core Sub-architecture: AVR19
• Kit Features: One Slider, One Wheel And 2
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

RES_8_BIT, 0u
HYST_6_25, RES_8_BIT, 0u );
The channel numbers 0,2,3,4,6,7 are allocated to pins 0,2,3,4,6,7 of (D,C) port pair respectively.
Pins 1 and 5 of ports C and D can be used for user application. Similarly the channel numbers
12,13,14,15 are allocated to pins 4,5,6,7 of (B,A) port pair respectively. Pins 1, 2, 3 and 4 of ports
B and A are again unused by the QTouch library and can be used for user application.
5.6.6.5
The Pull-up circuit available (in AVR devices) for each GPIO pin has to be disabled before
QTouch acquisition is performed. For tinyAVR and megaAVR devices the Pull-up circuit for all
GPIO port pins are enabled and disabled together. When user needs to configure the pins that
are not used by QTouch library for his application, he may enable the Pull-up circuit after QTouch
measurements are performed and disable them before the touch acquisition starts once again (as
shown in the code snippet below).
For XMEGA devices the Pull-up circuit for each individual GPIO port pins can be configured
individually, by writing to the PINnCTRL register of the ports being used.
5.6.7
5.6.7.1
QTouch acquisition method libraries are available for different port combinations.
Some of the key constraints while configuring the sensors are
/* Disable pull-ups for all pins */
MCUCR
/* perform QTouch measurements */
qt_measure_sensors ( current_time_ms_touch );
/* Enable pull-ups for all pins */
•
/* enable a slider on channels 2 to 4
qt_enable_slider( CHANNEL_2, CHANNEL_4, AKS_GROUP_1, 16u, HYST_6_25,
/* enable a key on channel 6 */
qt_enable_key( CHANNEL_6, AKS_GROUP_2, 10u, HYST_6_25 );
/* enable a key on channel 7 */
qt_enable_key( CHANNEL_7, AKS_GROUP_2, 10u, HYST_6_25 );
/* enable a rotor on channels 12 to14
qt_enable_rotor(
/* enable a key on channel 15 */
qt_enable_key( CHANNEL_15, AKS_GROUP_2, 10u, HYST_6_25 );
MCUCR
Constraints
Rotors/sliders have to be connected on three adjacent channels. (e.g. (1,2,3) or (3,4,5)
…) within the same port. Possible combinations are (0,1,2), (1,2,3) for a configuration
which supports 4 channels. Possible combinations (0,1,2), (1,2,3), (2,3,4), (3,4,5), (4,5,6),
(5,6,7) for a configuration which supports 8 channels.
Disabling and Enabling of Pull-up for AVR devices
QTouch acquisition method constraints
|=
&=
);
(1u << PUD);
~ (1u << PUD);
CHANNEL_12,
//MCUCR_PUD = 1u;
CHANNEL_14,
//MCUCR_PUD = 0u;
*/
*/
AKS_GROUP_1,
16u,
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